JPS58210603A - Method of producing substrate for variable resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that a resistor and an electrode part are connected to a resistor substrate formed on the surface thereof, a case covering an area other than the surface of the substrate, and a case that is fixed to the substrate and the case and connected to the electrode part. The present invention relates to a method for manufacturing a variable resistor substrate having negative and negative terminals.

In general, a variable resistor consists of a resistor substrate with a resistor and an electrode formed on its surface, a rotating shaft that is rotatably provided with respect to this substrate, and a resistor that is supported by this rotating shaft and that is connected to the resistor on the substrate. The variable resistor is equipped with a slider that rotates while making contact with the resistor, and when moisture resistance and dust resistance are required, a sealed variable resistor is used in which each of these parts is arranged inside a casing.

When configuring a sealed variable resistor, a case is provided that covers the area other than the surface of the resistor substrate, the case and the resistor substrate form a base, and the surface of the substrate is covered around the periphery of the case of the base. In many cases, a structure is adopted in which a covering cover is joined and a rotating shaft holding a slider is supported by the cover.

Conventionally, when manufacturing the base body of this type of variable resistor, first, as shown in FIG. 1(b), a case 2 holding the lead terminal 1 in a holding position is molded, and then the case 2 shown in FIG. (a) Insert the resistor board 3 indicated by K, and (c)
The gap formed between the case 2 and the board 3 as shown in
The board and case were integrated by injecting adhesive into the space d. Then, the lead terminals 1 passed through the holes 3a formed in the substrate 3 are bent toward the surface of the substrate, and each lead terminal is connected to the electrode portion on the surface of the substrate with solder 4. The lead terminal 1 and the substrate 3 constituted a variable resistor base 5. However, manufacturing a variable resistor substrate using the method described above requires a process of integrally molding the case and lead terminals, and a process of fixing the board inside the case, which requires a large number of man-hours. This has the disadvantage of increasing costs.

Furthermore, since the case and the resistor substrate are fixed with adhesive, there is a drawback that the strength of the bond between the two varies, resulting in non-uniform product quality.

In view of the above, the present invention reduces the number of man-hours by simultaneously molding the case, fixing the lead terminal to the case, and fixing the case and the resistor board in one step.
Bonding the Case and the Resistor Substrate The method for manufacturing the variable resistor substrate of the present invention will now be described in detail with reference to the drawings.

FIGS. 2(a) and 2(b) show an example of a molding apparatus for carrying out the manufacturing method of the present invention. It consists of a resin supply mechanism B that supplies synthetic resin. The mold A includes a first mold A1 to which the resin supply mechanism B is connected, and a resistor substrate 1.
A second mold A2 for positioning and fixing the first mold in a predetermined position;
The lead frame 12 together with the mold A1 and the second mold A2
and a fifth mold A3 for positioning and fixing the mold A, and a cavity C surrounded by the first to third molds AI to Am is constructed within this mold A. The resin supply mechanism B has a screw B2 disposed inside the main body Bl connected to the first mold A1, and the resin in the hopper BB attached to the main body B+Kl is fed into the cavity C by driving the screw B2. It is designed to be delivered within the

To carry out the method of the present invention using the above molding apparatus,
First, the resistor substrate 11 is positioned within the mold A as shown in FIG. 2(a). The resistor substrate 11 includes a resistor 11b having an arc-shaped pattern on the red surface of an insulating substrate 11a made of ceramic or the like, an intermediate electrode 11c, and terminal electrodes lid to ll.
f, and the intermediate electrode 11c is the resistor 11b.
It is formed in the center of the inside of the pattern. Further, the terminal electrodes lid to llf are provided at one end of the surface of the substrate 11, and the terminal electrodes lid and 11f on both sides are provided on the resistor 11.
At both ends of b, and at the center terminal electrode lie, there is an intermediate electrode 11
c. When positioning this resistor board 11 in the second mold A2, the human side of the resistor board 110 should be brought into close contact with the bottom surface of the second mold A2 to prevent resin from adhering to the surface of the resistor board. . Next, a lead frame 12 is prepared in which the lead terminals 12a to 12c connected to the terminal electrodes lid to 11f, respectively, are connected by frames 12d and 12d, and the lead terminals 12a to 12c of this lead frame 12 are connected to the terminal electrodes lid to 11f, respectively. 〜llf, and align the first mold A with the second mold A, and align the third mold A3 with the first and second molds A1 and A2. to combine these types with each other. An insulating resin is injected into the ridge cavity C, and the resin is hardened. After the resin in the cavity C has hardened, the molds are separated from each other and the resistor substrate 11 and lead frame 12 are separated, as shown in FIG.
The molded material consisting of the case 13 and the case 13 is taken out. In this molded product, as shown in FIGS. 3(a) to 3(e), lead terminals 12a to 12c corresponding to respective terminal electrodes lid to 11f of the resistor substrate 11 are connected to a frame 12d,
12d, the frame 12 is cut at the position shown by the dashed line A and the opening shown in FIG. 3(C).
d and 12d are separated from each lead terminal 12a to 12c. Next, bend the ends of the lead terminals 12a to 12c of the molded material corresponding to the terminal electrodes lid to llf, and solder the solder 14.
Corresponding lead terminals 12a to 12c and terminal electrode l
id to llf are electrically connected to form a variable resistor base 1.
Complete step 5 (see Figure 4).

FIG. 5 shows an example of a variable resistor assembled using the variable resistor base manufactured as described above. In the same figure, reference numeral 16 denotes a cover made of insulating resin, the lower end of which is glued to the periphery of the case 13 and integrated with the case, and the cover 6 - 16 and the case 13 seal the variable resistor. is configured. The cover 16 has a hollow portion having a circular cross section, and a rotating body 17 is rotatably fitted into the hollow portion. The rotating body 17 has a shaft portion 17a at its end, and this shaft portion 17a is inserted into the hole 1 provided in the bottom wall of the cover 16.
A slot 17b is formed in the end surface of the shaft portion 17a to engage the bit of the driver. cover 1
There is an OIJ ring 1 between the rotating body 17 and the rotating body 17 near the hole 16a of 6.
8 is interposed therebetween, and the inside of the cover 16 is sealed by this O-ring 18. A slider 19 is held on the cover 16, and this slider contacts the resistor 11b on the resistor substrate 11 and the intermediate terminal electrode 11c while moving the substrate 11.
It is designed to slide on the top. Lead terminal 12a~
The lead terminals 12a + 12c at both ends of 12c are bent in a direction parallel to the board surface of the board 11, and the central lead terminal 12b is bent in a direction perpendicular to the board surface of the board 11, and then bent in a direction parallel to the board surface of the board 11. is bent in a direction parallel to the

As in the above example, in the method of manufacturing a variable resistor substrate, if the case is molded with the lead frame aligned with the end of the resistor substrate, the lead terminals can be inserted into the resistor substrate as in the conventional method. Since there is no need to form holes for this purpose, it is possible to use a substrate made of a material such as ceramic that is difficult to drill.

Although the resin supply mechanism B used in the above embodiment is a resin extruder, it goes without saying that the resin supply mechanism B may also be an injection machine that injects the resin into the cavity.

As described above, according to the manufacturing method of the present invention, when molding the case, the case, the resistor board, and the lead terminal are integrally molded at the same time, so it is possible to reduce the number of man-hours and reduce costs. . Furthermore, since the bonding strength between the case and the resistor substrate becomes uniform, quality can be stabilized in terms of mechanical strength and dimensions; there is a vf+ point.

[Brief explanation of the drawing]

Fig. 1(a) is a perspective view of a conventional resistor substrate, Fig. 1(b) is a perspective view of a case with a conventional lead terminal, and Fig. 1(c) is a vertical cross-section of a conventional variable resistor substrate. Front view, 2nd
Figures (a) and (b) are explanatory diagrams explaining the manufacturing method of the present invention, respectively, and Figures 5 (a), (b), and (c) are moldings shown in Figures 2 (a) and (b), respectively. A plan view showing a molded product manufactured by the apparatus, mb-i in the same figure (a)
A cross-sectional view along the nb line and a cross-sectional view along the u[c-IUa line in FIG. FIG. 2 is a longitudinal cross-sectional view showing an example of a variable resistor assembled using a variable resistor base manufactured by. 11...Resistor board, llb...Resistor, lid~
11f...Terminal electrode, 12a-12c...Lead terminal, 13...Case, 15...Base for variable resistor,
A...Mold. 9-11 yen-A・)-'mil ÷. 12

Claims (1)

[Claims] A resistor substrate having a resistor for a variable resistor and an electrode portion formed on its surface, a case made of an insulating resin that covers an area other than the surface of the substrate, and a case fixed to the substrate and the case and connected to the electrode portion. In the method of manufacturing a variable resistor substrate having lead terminals, the resistor substrate and the lead terminals are inserted into a mold for molding the case, and resin is injected into the mold to mold the case. A method for manufacturing a variable resistor base, characterized in that the lead terminal and the board are integrated with the case at the same time as molding.